Tunnel Vision | Hidden Brain Have you ever noticed that when something important is missing in your life, your brain can only seem to focus on that missing thing? Two researchers have dubbed this phenomenon "scarcity."

"It leads you to take certain behaviors that in the short term help you to manage scarcity, but in the long term only make matters worse," says Sendhil Mullainathan, an economics professor at Harvard University.

Several years ago, he and Eldar Shafir, a psychology professor at Princeton, started researching this idea. Their theory was this: When you're really desperate for something, you can focus on it so obsessively there's no room for anything else. The time-starved spend much of their mental energy juggling time. People with little money worry constantly about making ends meet.

Scarcity takes a huge toll. It robs people of insight. And it helps to explain why, when we're in a hole, we sometimes dig ourselves even deeper.

This week on Hidden Brain, we'll explore the concept of scarcity and how it affects people across the globe — from sugar cane farmers in India to time-starved physicians in the United States.

Hidden Brain is hosted by Shankar Vedantam and produced by Jennifer Schmidt, Rhaina Cohen, Parth Shah, and Laura Kwerel. Our supervising producer is Tara Boyle. You can follow us on Twitter @hiddenbrain, and listen for Hidden Brain stories each week on your local public radio station.